/**
 * @license AngularJS v1.2.4
 * (c) 2010-2014 Google, Inc. http://angularjs.org
 * License: MIT
 */
(function (window, angular, undefined) {
    'use strict';

    /**
     * @ngdoc overview
     * @name ngTouch
     * @description
     *
     * # ngTouch
     *
     * The `ngTouch` module provides touch events and other helpers for touch-enabled devices.
     * The implementation is based on jQuery Mobile touch event handling
     * ([jquerymobile.com](http://jquerymobile.com/)).
     *
     * {@installModule touch}
     *
     * See {@link ngTouch.$swipe `$swipe`} for usage.
     *
     * <div doc-module-components="ngTouch"></div>
     *
     */

// define ngTouch module
    /* global -ngTouch */
    var ngTouch = angular.module('ngTouch', []);

    /* global ngTouch: false */

    /**
     * @ngdoc object
     * @name ngTouch.$swipe
     *
     * @description
     * The `$swipe` service is a service that abstracts the messier details of hold-and-drag swipe
     * behavior, to make implementing swipe-related directives more convenient.
     *
     * Requires the {@link ngTouch `ngTouch`} module to be installed.
     *
     * `$swipe` is used by the `ngSwipeLeft` and `ngSwipeRight` directives in `ngTouch`, and by
     * `ngCarousel` in a separate component.
     *
     * # Usage
     * The `$swipe` service is an object with a single method: `bind`. `bind` takes an element
     * which is to be watched for swipes, and an object with four handler functions. See the
     * documentation for `bind` below.
     */

    ngTouch.factory('$swipe', [function () {
        // The total distance in any direction before we make the call on swipe vs. scroll.
        var MOVE_BUFFER_RADIUS = 10;

        function getCoordinates(event) {
            var touches = event.touches && event.touches.length ? event.touches : [event];
            var e = (event.changedTouches && event.changedTouches[0]) ||
                (event.originalEvent && event.originalEvent.changedTouches &&
                event.originalEvent.changedTouches[0]) ||
                touches[0].originalEvent || touches[0];

            return {
                x: e.clientX,
                y: e.clientY
            };
        }

        return {
            /**
             * @ngdoc method
             * @name ngTouch.$swipe#bind
             * @methodOf ngTouch.$swipe
             *
             * @description
             * The main method of `$swipe`. It takes an element to be watched for swipe motions, and an
             * object containing event handlers.
             *
             * The four events are `start`, `move`, `end`, and `cancel`. `start`, `move`, and `end`
             * receive as a parameter a coordinates object of the form `{ x: 150, y: 310 }`.
             *
             * `start` is called on either `mousedown` or `touchstart`. After this event, `$swipe` is
             * watching for `touchmove` or `mousemove` events. These events are ignored until the total
             * distance moved in either dimension exceeds a small threshold.
             *
             * Once this threshold is exceeded, either the horizontal or vertical delta is greater.
             * - If the horizontal distance is greater, this is a swipe and `move` and `end` events follow.
             * - If the vertical distance is greater, this is a scroll, and we let the browser take over.
             *   A `cancel` event is sent.
             *
             * `move` is called on `mousemove` and `touchmove` after the above logic has determined that
             * a swipe is in progress.
             *
             * `end` is called when a swipe is successfully completed with a `touchend` or `mouseup`.
             *
             * `cancel` is called either on a `touchcancel` from the browser, or when we begin scrolling
             * as described above.
             *
             */
            bind: function (element, eventHandlers) {
                // Absolute total movement, used to control swipe vs. scroll.
                var totalX, totalY;
                // Coordinates of the start position.
                var startCoords;
                // Last event's position.
                var lastPos;
                // Whether a swipe is active.
                var active = false;

                element.on('touchstart mousedown', function (event) {
                    startCoords = getCoordinates(event);
                    active = true;
                    totalX = 0;
                    totalY = 0;
                    lastPos = startCoords;
                    eventHandlers['start'] && eventHandlers['start'](startCoords, event);
                });

                element.on('touchcancel', function (event) {
                    active = false;
                    eventHandlers['cancel'] && eventHandlers['cancel'](event);
                });

                element.on('touchmove mousemove', function (event) {
                    if (!active) return;

                    // Android will send a touchcancel if it thinks we're starting to scroll.
                    // So when the total distance (+ or - or both) exceeds 10px in either direction,
                    // we either:
                    // - On totalX > totalY, we send preventDefault() and treat this as a swipe.
                    // - On totalY > totalX, we let the browser handle it as a scroll.

                    if (!startCoords) return;
                    var coords = getCoordinates(event);

                    totalX += Math.abs(coords.x - lastPos.x);
                    totalY += Math.abs(coords.y - lastPos.y);

                    lastPos = coords;

                    if (totalX < MOVE_BUFFER_RADIUS && totalY < MOVE_BUFFER_RADIUS) {
                        return;
                    }

                    // One of totalX or totalY has exceeded the buffer, so decide on swipe vs. scroll.
                    if (totalY > totalX) {
                        // Allow native scrolling to take over.
                        active = false;
                        eventHandlers['cancel'] && eventHandlers['cancel'](event);
                        return;
                    } else {
                        // Prevent the browser from scrolling.
                        event.preventDefault();
                        eventHandlers['move'] && eventHandlers['move'](coords, event);
                    }
                });

                element.on('touchend mouseup', function (event) {
                    if (!active) return;
                    active = false;
                    eventHandlers['end'] && eventHandlers['end'](getCoordinates(event), event);
                });
            }
        };
    }]);

    /* global ngTouch: false */

    /**
     * @ngdoc directive
     * @name ngTouch.directive:ngClick
     *
     * @description
     * A more powerful replacement for the default ngClick designed to be used on touchscreen
     * devices. Most mobile browsers wait about 300ms after a tap-and-release before sending
     * the click event. This version handles them immediately, and then prevents the
     * following click event from propagating.
     *
     * Requires the {@link ngTouch `ngTouch`} module to be installed.
     *
     * This directive can fall back to using an ordinary click event, and so works on desktop
     * browsers as well as mobile.
     *
     * This directive also sets the CSS class `ng-click-active` while the element is being held
     * down (by a mouse click or touch) so you can restyle the depressed element if you wish.
     *
     * @element ANY
     * @param {expression} ngClick {@link guide/expression Expression} to evaluate
     * upon tap. (Event object is available as `$event`)
     *
     * @example
     <doc:example>
     <doc:source>
     <button ng-click="count = count + 1" ng-init="count=0">
     Increment
     </button>
     count: {{ count }}
     </doc:source>
     </doc:example>
     */

    ngTouch.config(['$provide', function ($provide) {
        $provide.decorator('ngClickDirective', ['$delegate', function ($delegate) {
            // drop the default ngClick directive
            $delegate.shift();
            return $delegate;
        }]);
    }]);

    ngTouch.directive('ngClick', ['$parse', '$timeout', '$rootElement',
        function ($parse, $timeout, $rootElement) {
            var TAP_DURATION = 750; // Shorter than 750ms is a tap, longer is a taphold or drag.
            var MOVE_TOLERANCE = 12; // 12px seems to work in most mobile browsers.
            var PREVENT_DURATION = 2500; // 2.5 seconds maximum from preventGhostClick call to click
            var CLICKBUSTER_THRESHOLD = 25; // 25 pixels in any dimension is the limit for busting clicks.

            var ACTIVE_CLASS_NAME = 'ng-click-active';
            var lastPreventedTime;
            var touchCoordinates;


            // TAP EVENTS AND GHOST CLICKS
            //
            // Why tap events?
            // Mobile browsers detect a tap, then wait a moment (usually ~300ms) to see if you're
            // double-tapping, and then fire a click event.
            //
            // This delay sucks and makes mobile apps feel unresponsive.
            // So we detect touchstart, touchmove, touchcancel and touchend ourselves and determine when
            // the user has tapped on something.
            //
            // What happens when the browser then generates a click event?
            // The browser, of course, also detects the tap and fires a click after a delay. This results in
            // tapping/clicking twice. So we do "clickbusting" to prevent it.
            //
            // How does it work?
            // We attach global touchstart and click handlers, that run during the capture (early) phase.
            // So the sequence for a tap is:
            // - global touchstart: Sets an "allowable region" at the point touched.
            // - element's touchstart: Starts a touch
            // (- touchmove or touchcancel ends the touch, no click follows)
            // - element's touchend: Determines if the tap is valid (didn't move too far away, didn't hold
            //   too long) and fires the user's tap handler. The touchend also calls preventGhostClick().
            // - preventGhostClick() removes the allowable region the global touchstart created.
            // - The browser generates a click event.
            // - The global click handler catches the click, and checks whether it was in an allowable region.
            //     - If preventGhostClick was called, the region will have been removed, the click is busted.
            //     - If the region is still there, the click proceeds normally. Therefore clicks on links and
            //       other elements without ngTap on them work normally.
            //
            // This is an ugly, terrible hack!
            // Yeah, tell me about it. The alternatives are using the slow click events, or making our users
            // deal with the ghost clicks, so I consider this the least of evils. Fortunately Angular
            // encapsulates this ugly logic away from the user.
            //
            // Why not just put click handlers on the element?
            // We do that too, just to be sure. The problem is that the tap event might have caused the DOM
            // to change, so that the click fires in the same position but something else is there now. So
            // the handlers are global and care only about coordinates and not elements.

            // Checks if the coordinates are close enough to be within the region.
            function hit(x1, y1, x2, y2) {
                return Math.abs(x1 - x2) < CLICKBUSTER_THRESHOLD && Math.abs(y1 - y2) < CLICKBUSTER_THRESHOLD;
            }

            // Checks a list of allowable regions against a click location.
            // Returns true if the click should be allowed.
            // Splices out the allowable region from the list after it has been used.
            function checkAllowableRegions(touchCoordinates, x, y) {
                for (var i = 0; i < touchCoordinates.length; i += 2) {
                    if (hit(touchCoordinates[i], touchCoordinates[i + 1], x, y)) {
                        touchCoordinates.splice(i, i + 2);
                        return true; // allowable region
                    }
                }
                return false; // No allowable region; bust it.
            }

            // Global click handler that prevents the click if it's in a bustable zone and preventGhostClick
            // was called recently.
            function onClick(event) {
                if (Date.now() - lastPreventedTime > PREVENT_DURATION) {
                    return; // Too old.
                }

                var touches = event.touches && event.touches.length ? event.touches : [event];
                var x = touches[0].clientX;
                var y = touches[0].clientY;
                // Work around desktop Webkit quirk where clicking a label will fire two clicks (on the label
                // and on the input element). Depending on the exact browser, this second click we don't want
                // to bust has either (0,0) or negative coordinates.
                if (x < 1 && y < 1) {
                    return; // offscreen
                }

                // Look for an allowable region containing this click.
                // If we find one, that means it was created by touchstart and not removed by
                // preventGhostClick, so we don't bust it.
                if (checkAllowableRegions(touchCoordinates, x, y)) {
                    return;
                }

                // If we didn't find an allowable region, bust the click.
                event.stopPropagation();
                event.preventDefault();

                // Blur focused form elements
                event.target && event.target.blur();
            }


            // Global touchstart handler that creates an allowable region for a click event.
            // This allowable region can be removed by preventGhostClick if we want to bust it.
            function onTouchStart(event) {
                var touches = event.touches && event.touches.length ? event.touches : [event];
                var x = touches[0].clientX;
                var y = touches[0].clientY;
                touchCoordinates.push(x, y);

                $timeout(function () {
                    // Remove the allowable region.
                    for (var i = 0; i < touchCoordinates.length; i += 2) {
                        if (touchCoordinates[i] == x && touchCoordinates[i + 1] == y) {
                            touchCoordinates.splice(i, i + 2);
                            return;
                        }
                    }
                }, PREVENT_DURATION, false);
            }

            // On the first call, attaches some event handlers. Then whenever it gets called, it creates a
            // zone around the touchstart where clicks will get busted.
            function preventGhostClick(x, y) {
                if (!touchCoordinates) {
                    $rootElement[0].addEventListener('click', onClick, true);
                    $rootElement[0].addEventListener('touchstart', onTouchStart, true);
                    touchCoordinates = [];
                }

                lastPreventedTime = Date.now();

                checkAllowableRegions(touchCoordinates, x, y);
            }

            // Actual linking function.
            return function (scope, element, attr) {
                var clickHandler = $parse(attr.ngClick),
                    tapping = false,
                    tapElement,  // Used to blur the element after a tap.
                    startTime,   // Used to check if the tap was held too long.
                    touchStartX,
                    touchStartY;

                function resetState() {
                    tapping = false;
                    element.removeClass(ACTIVE_CLASS_NAME);
                }

                element.on('touchstart', function (event) {
                    tapping = true;
                    tapElement = event.target ? event.target : event.srcElement; // IE uses srcElement.
                    // Hack for Safari, which can target text nodes instead of containers.
                    if (tapElement.nodeType == 3) {
                        tapElement = tapElement.parentNode;
                    }

                    element.addClass(ACTIVE_CLASS_NAME);

                    startTime = Date.now();

                    var touches = event.touches && event.touches.length ? event.touches : [event];
                    var e = touches[0].originalEvent || touches[0];
                    touchStartX = e.clientX;
                    touchStartY = e.clientY;
                });

                element.on('touchmove', function (event) {
                    resetState();
                });

                element.on('touchcancel', function (event) {
                    resetState();
                });

                element.on('touchend', function (event) {
                    var diff = Date.now() - startTime;

                    var touches = (event.changedTouches && event.changedTouches.length) ? event.changedTouches :
                        ((event.touches && event.touches.length) ? event.touches : [event]);
                    var e = touches[0].originalEvent || touches[0];
                    var x = e.clientX;
                    var y = e.clientY;
                    var dist = Math.sqrt(Math.pow(x - touchStartX, 2) + Math.pow(y - touchStartY, 2));

                    if (tapping && diff < TAP_DURATION && dist < MOVE_TOLERANCE) {
                        // Call preventGhostClick so the clickbuster will catch the corresponding click.
                        preventGhostClick(x, y);

                        // Blur the focused element (the button, probably) before firing the callback.
                        // This doesn't work perfectly on Android Chrome, but seems to work elsewhere.
                        // I couldn't get anything to work reliably on Android Chrome.
                        if (tapElement) {
                            tapElement.blur();
                        }

                        if (!angular.isDefined(attr.disabled) || attr.disabled === false) {
                            element.triggerHandler('click', [event]);
                        }
                    }

                    resetState();
                });

                // Hack for iOS Safari's benefit. It goes searching for onclick handlers and is liable to click
                // something else nearby.
                element.onclick = function (event) {
                };

                // Actual click handler.
                // There are three different kinds of clicks, only two of which reach this point.
                // - On desktop browsers without touch events, their clicks will always come here.
                // - On mobile browsers, the simulated "fast" click will call this.
                // - But the browser's follow-up slow click will be "busted" before it reaches this handler.
                // Therefore it's safe to use this directive on both mobile and desktop.
                element.on('click', function (event, touchend) {
                    scope.$apply(function () {
                        clickHandler(scope, {$event: (touchend || event)});
                    });
                });

                element.on('mousedown', function (event) {
                    element.addClass(ACTIVE_CLASS_NAME);
                });

                element.on('mousemove mouseup', function (event) {
                    element.removeClass(ACTIVE_CLASS_NAME);
                });

            };
        }]);

    /* global ngTouch: false */

    /**
     * @ngdoc directive
     * @name ngTouch.directive:ngSwipeLeft
     *
     * @description
     * Specify custom behavior when an element is swiped to the left on a touchscreen device.
     * A leftward swipe is a quick, right-to-left slide of the finger.
     * Though ngSwipeLeft is designed for touch-based devices, it will work with a mouse click and drag
     * too.
     *
     * Requires the {@link ngTouch `ngTouch`} module to be installed.
     *
     * @element ANY
     * @param {expression} ngSwipeLeft {@link guide/expression Expression} to evaluate
     * upon left swipe. (Event object is available as `$event`)
     *
     * @example
     <doc:example>
     <doc:source>
     <div ng-show="!showActions" ng-swipe-left="showActions = true">
     Some list content, like an email in the inbox
     </div>
     <div ng-show="showActions" ng-swipe-right="showActions = false">
     <button ng-click="reply()">Reply</button>
     <button ng-click="delete()">Delete</button>
     </div>
     </doc:source>
     </doc:example>
     */

    /**
     * @ngdoc directive
     * @name ngTouch.directive:ngSwipeRight
     *
     * @description
     * Specify custom behavior when an element is swiped to the right on a touchscreen device.
     * A rightward swipe is a quick, left-to-right slide of the finger.
     * Though ngSwipeRight is designed for touch-based devices, it will work with a mouse click and drag
     * too.
     *
     * Requires the {@link ngTouch `ngTouch`} module to be installed.
     *
     * @element ANY
     * @param {expression} ngSwipeRight {@link guide/expression Expression} to evaluate
     * upon right swipe. (Event object is available as `$event`)
     *
     * @example
     <doc:example>
     <doc:source>
     <div ng-show="!showActions" ng-swipe-left="showActions = true">
     Some list content, like an email in the inbox
     </div>
     <div ng-show="showActions" ng-swipe-right="showActions = false">
     <button ng-click="reply()">Reply</button>
     <button ng-click="delete()">Delete</button>
     </div>
     </doc:source>
     </doc:example>
     */

    function makeSwipeDirective(directiveName, direction, eventName) {
        ngTouch.directive(directiveName, ['$parse', '$swipe', function ($parse, $swipe) {
            // The maximum vertical delta for a swipe should be less than 75px.
            var MAX_VERTICAL_DISTANCE = 75;
            // Vertical distance should not be more than a fraction of the horizontal distance.
            var MAX_VERTICAL_RATIO = 0.3;
            // At least a 30px lateral motion is necessary for a swipe.
            var MIN_HORIZONTAL_DISTANCE = 30;

            return function (scope, element, attr) {
                var swipeHandler = $parse(attr[directiveName]);

                var startCoords, valid;

                function validSwipe(coords) {
                    // Check that it's within the coordinates.
                    // Absolute vertical distance must be within tolerances.
                    // Horizontal distance, we take the current X - the starting X.
                    // This is negative for leftward swipes and positive for rightward swipes.
                    // After multiplying by the direction (-1 for left, +1 for right), legal swipes
                    // (ie. same direction as the directive wants) will have a positive delta and
                    // illegal ones a negative delta.
                    // Therefore this delta must be positive, and larger than the minimum.
                    if (!startCoords) return false;
                    var deltaY = Math.abs(coords.y - startCoords.y);
                    var deltaX = (coords.x - startCoords.x) * direction;
                    return valid && // Short circuit for already-invalidated swipes.
                        deltaY < MAX_VERTICAL_DISTANCE &&
                        deltaX > 0 &&
                        deltaX > MIN_HORIZONTAL_DISTANCE &&
                        deltaY / deltaX < MAX_VERTICAL_RATIO;
                }

                $swipe.bind(element, {
                    'start': function (coords, event) {
                        startCoords = coords;
                        valid = true;
                    },
                    'cancel': function (event) {
                        valid = false;
                    },
                    'end': function (coords, event) {
                        if (validSwipe(coords)) {
                            scope.$apply(function () {
                                element.triggerHandler(eventName);
                                swipeHandler(scope, {$event: event});
                            });
                        }
                    }
                });
            };
        }]);
    }

// Left is negative X-coordinate, right is positive.
    makeSwipeDirective('ngSwipeLeft', -1, 'swipeleft');
    makeSwipeDirective('ngSwipeRight', 1, 'swiperight');


})(window, window.angular);
